The present invention relates to determining basal metabolism of a patient, and more particularly, to an apparatus for measuring basal metabolism using fat-free mass.
Expensive and extensive apparatus are usually necessary to determine accurate basal metabolism of a subject. Additionally, many loads and measuring conditions are required, and a subject has to keep at rest for a long time with wearing a facemask and a mouthpiece. In addition, only a specialist can handle the measuring apparatus and evaluate the measured results. As such, the general public can hardly perform their own tests to obtain an accurate measure of their own basal metabolism.
For these reasons, a statistically standard basal metabolism value is used in most cases to determine basal metabolism. The statistically standard basal metabolism value is obtained, for example in Japan, by multiplying a reference value of basal metabolism on the basis of gender and age according to Health Service Bureau of Ministry of Health and Welfare by body weight. This standard value is used despite the importance of a relationship between adiposis and basal metabolism.
Basal metabolism, however, is considered to be directly proportional to fat-free mass rather than to actual body weight. As shown in FIG. 1, the basal metabolism determined using the above-mentioned method is suitable for a human having a standard body build and a standard body composition, because body composition is a strong effective factor. However, a calculated value of basal metabolism tends to be higher than an observed value of basal metabolism in a pycnic type (i.e., a human with a high fat rate) who has a heavy body weight and a large amount of fat. Also, a calculated value of basal metabolism tends to be lower than an observed value of basal metabolism in a slim and muscular man (i.e., a human with a low fat rate). Therefore, the above-mentioned method for calculating basal metabolism is not preferable from the viewpoint of guidance for adiposis.
Since basal metabolism has a close relation to the fat-free mass, a formula represented as follows is employed in a foreign nutrition science academy.
BMR=Axc3x97FFM+B
BMR is basal metabolism (kcal/day), FFM is fat-free mass (kg), and A and B are constants. The relationship between the basal metabolism and the fat-free mass is shown in FIG. 2. This formula produces a correlation coefficient of 0.824, which shows the formula closely correlates with observed results. However, the basal metabolism obtained with the above mentioned formula is adapted to adults but not to children in a growth period. In addition, the calculated value with the formula tends to be lower than an observed value in a person having a low fat-free mass, especially in young slim females according to the measured results by the present inventors. Accordingly, a need exists for an improved apparatus for calculating basal metabolism that provides a calculated value that more accurately correlates with the observed value of basal metabolism so that guidance can be effectively provided as to diet and exercise for a pycnic type person and also to children.
These and other needs are met by embodiments of the present invention which provide an apparatus for measuring basal metabolism. The apparatus includes a device to input individual data, for example an age of a subject; a device to measure bioelectrical impedance of the subject; a device for calculation of fat-free mass on the basis of the individual data and the impedance; and a device for calculation of basal metabolism of the subject on the basis of a reciprocal of the age and the fat-free mass. By adding the reciprocal of an age as a factor in determining basal metabolism, in addition to fat-free mass, the present invention improves the accuracy of an arithmetic method used to determine basal metabolism.
In an aspect of the present invention, basal metabolism can be determined using the formula represented by BMR=Axc3x97FFM+Bxc3x97(1/age)+C, in which BMR is basal metabolism (kcal/day), FFM is fat-free mass (kg), and A, B, and C are constants.
In accordance with another aspect of the present invention, the device can determine basal metabolism using the formula represented by BMR=Axc3x97FFM2+Bxc3x97FFM+Cxc3x97(1/age)+D, in which BMR is basal metabolism (kcal/day), FFM is fat-free mass (kg), and A, B, C, and D are constants.
In an additional embodiment, the invention includes a device to input individual data, for example age and body weight of a subject; a device to measure bioelectrical impedance of the subject; a device for calculation of fat-free mass on the basis of a reciprocal of the individual data and the impedance; and a device for calculation of basal metabolism of the subject on the basis of the age, the body weight, and the fat-free mass. By adding both age and weight as factors in determining basal metabolism, in addition to fat-free mass, the present invention improves the accuracy of an arithmetic method used to determine basal metabolism.
In an aspect of the invention, the basal metabolism can be determined using the formula represented by BMR=Axc3x97FFM+Bxc3x97(1/age)+Cxc3x97body weight+D, in which BMR is basal metabolism (kcal/day), FFM is fat-free mass (kg), and A, B, C, and D are constants.
In another aspect of the invention, the basal metabolism is calculated with a formula represented by BMR=Axc3x97FFM2+Bxc3x97FFM+Cxc3x97(1/age)+Dxc3x97body weight+E, in which BMR is basal metabolism (kcal/day), FFM is fat-free mass(kg), and A, B, C, D, and E are constants.
In other aspects of the invention, the present invention is a portable apparatus without a weighing machine in which the subject""s body weight is manually inputted into the input device. Alternatively, the subject""s body weight can be inputted as a signal from a device that measures body weight. Still further, the body fat measuring assembly can be attached to a weighing machine and the subject""s body weight can be inputted as a signal simultaneously to when the impedance is measured.
Additional advantages of the present invention will become readily apparent to those skilled in this art from the following detailed description, wherein only the preferred embodiment of the present invention is shown and described, simply by way of illustration of the best mode contemplated for carrying out the present invention. As will be realized, the present invention is capable of other and different embodiments, and its several details are capable of modifications in various obvious respects, all without departing from the invention. Accordingly, the drawings and description are to be regarded as illustrative in nature, and not as restrictive.